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Wednesday, October 24, 2012

Another good day on the 10 metre band with the solar flux at 144. The photo above shows the 57 WSPR stations heard on 28 MHz between the time the band opened at 7:34 UTC and closed at 19:56 UTC.

Points to note....
1) Lots of spots from Australia including Tasmania :o)
2) I heard a station in Japan for the first time on WSPR on 10m! Note the Northerly path. Japan on 10m was pretty common at the peak of the last solar cycle back in 2001. Those northerly paths are still proving difficult at the moment with the flux at 144.
3) Absence of signals from Africa and South America has more to do with a lack of stations using WSPR rather than a lack of propagation.
4) The band opened to the NW coast of the US which again is a Northerly path and a good sign. It was open to the same area the previous day as well.
5) Backscatter.......every day now, I am hearing stations in the UK. A while back, I was wondering if the mode of propagation was tropo, aircraft scatter or Sporadic-E? Now I'd be almost certain that it's F2 backscatter. It seems to be remarkably consistent day after day. If the band is open then the backscatter is present. The thing is that WSPR is hearing signals that are normally buried in the noise.

These are the stations in the UK heard on the 23rd of Oct via backscatter. Most are using 5 watts. G4ILO had 2 watts into an attic dipole...

Tuesday, October 23, 2012

Over the last week or so, I have at times seen an odd looking signal while using WSPR on 28 MHz. It starts off about 10 Hz too low in frequency and then drifts upwards for about 30 seconds and then stays reasonably steady for the remaining 90 seconds of the WSPR two minute time period.

When I first saw this signal, I wasn't getting any decodes but eventually, it came through.....it was GW7KNF in West Wales on backscatter. I have no idea as to why his signal drifts at the start but it is unique to his signal.

Normally, I think a signal needs to drift less than 4 Hz to be decoded. Considering that at least 20% of his signal exceeds this then perhaps you don't need to hear the full two minutes of the signal to decode it? Going on the above example, it looks about 90 seconds.

Sunday, October 21, 2012

While it's nice to see the stations coming through from Australia and the West coast of the US, the one that really caught my attention was ZL3PX from New Zealand. Considering that it is at the opposite end of the globe as viewed from Ireland, it's reasonably rare on 28 MHz.

Friday, October 19, 2012

I got an e-mail this morning with the link to new IRTS newsletter. Looking through some of the news items, I came across a link to this video showing the new tower for the East Cork Radio Club contest station, EI7M.

His signal was very weak, maybe 4/1 to 4/2 at best. He was working a pile up and it was obvious that he was getting into the UK and Ireland pretty well. I gave him a call towards the end......managed to get a EI7?? back but then he dived into the noise. I think it was probably just at the end of the opening.

But I was curious. How did the signal get from Hawaii to Ireland?

This is the short path shown above. It almost certainly wasn't short path as the band hadn't opened to the US and the North-West yet. What about long path? Did the signal travel over the South Pacific, over Antarctica and then over Africa???

Or was it a skewed path? From somewhere over the Indian Ocean? I have heard of this before whereby European stations work Japan on 50 MHz by beaming at the Indian Ocean. Not long after hearing NH7O, I could hear the Australian beacon VK8VF/B near Darwin. Earlier, I was hearing the Phillipines on WSPR so the band was certainly open to that part of the world.

Wonder what way people were beaming when they worked him? It's kind of hard for me to tell with my vertical ;o)

Wednesday, October 17, 2012

Over the last week or so, the solar flux had dropped down to around the 100 mark and there was a distinct lack of good East-West propagation. On the 16th, the flux was back up to 137 and the band really opened nicely to the USA...

There seems to have been some Sporadic-E signals from Europe as well. In fact, there seems to be plenty of weak Sp-E around most days.

Almost every day as well for the last week, I have heard WSPR signals from stations in the UK. The only pattern is that they seem to coincide with good Sp-E conditions to Europe or good F2 conditions. I would say at this stage that I am pretty sure that they are via back scatter rather than some other mode.

Friday, October 12, 2012

I came across this amazing resource recently. 73 magazine was an amateur radio publication that ran from October 1960 to September 2003. In total, there were 513 issues and they are all available now for free in PDF format.

One of the main reasons I have this blog is to act as a scratchpad for myself. If something happens that I want to make a note of, then it's a handy place to keep a record of it and if it helps someone else fix a problem that they are having then so much the better.

On the morning of the 11th of October, I was receiving a station as shown above but I was getting no decodes. Looking at the database on the WSPR website and the spots from other stations, it seemed as if the station was EA8FF, someone who I have heard and decoded over the last few days.

I switched the rig to 30m and left it listening to the WSPR signals there for about 10 minutes. No decodes. So obviously, WSPR had stopped working.

Solution.......it turned out that the sound card in the PC seemed to have crashed or at least the micropart part of it. It was a simple case of rebooting the PC and everything worked fine again.

Wednesday, October 10, 2012

I came across this video clip recently from the BBC about the vital part that radio amateurs played in wartime Britain by listening in to coded German traffic on the short wave bands.
The programme was broadcast in 1979 which was 33 years ago, about the same amount of time from when the events happened in WW2.

The question is how? I presume it is F2 backscatter as I often hear EA8FF at the same time (as can be seen from the bright trace in the WSPR display above) but why haven't I seen any other spots from other UK stations in the three days?

I sent Phil, GW7PEO an e-mail to enquire about his working conditions on 28 MHz and he very kindly replied. Power = 8 watts......which after compensating for coax losses gives about 5w at the antenna which is a multi-band vertical. Good low take off to the mountains to the south/south-west....i.e. in my direction.

If the signal was direct via tropo then I'd expect to have seen more spots. Backscatter via F2 is probably the most likely explanation. It got me thinking though if it was at all possible that it might be from aircraft scatter? GW7PEO is very close to the flight path for planes going from Dublin/Belfast to London.

The problem with the aircraft scatter theory is that there will be a certain amount of doppler shift on the signal, even at 28 MHz. The maximum amount of drift allowed on a WSPR signal is about 4 Hz. If I understood the figures correctly with an online calculator, the maximum amount of doppler at 28 MHz from an aircraft doing about 800 kph is about 19 Hz. Unless of course if the plane was going at right angles to the direct path between the two stations in which case, the doppler shift would be a lot less.

On SSB, I heard VU3RAZ in India and A4 and A6 stations in the Middle East. Also, lots of Russian and Ukraine stations at one F2 hop distance.

As the map shows above, there was some Sporadic-E as well with some of the closer European staions in Germany and Spain making it through. Later, it opened to the USA again, the first time really since last Sunday and the aurora on Sunday night. The one of interest here was N6OIL making it through from California...

Again, EA8FF was being heard at the same time with a reasonable signal indicating good conditions to the south. In reality, the back scatter could be from anywhere....south? south-west? south-east? Today, the spot from GW7TEO was at 13:44 UTC. The two spots from yesterday were at 14:30 and 14:52 UTC.

Overall.....some notes...
1) Over the last few days that I have been listening on the 10 metre band, the Solar Flux index has been around the 120-130 mark.
2) Lot's of multi-hop F2 conditions but very variable. Open to different areas on different days.
3) The most consistent signals as expected are the single hop F2 ones....East Mediterranean, Russia.
4) The most consistent beacons are those around the 3,250 to 3,750 km mark. e.g. 5B4CY/B in Cyrus, SV5TEN/B in Rhodes.
5) When conditions on 28 Mhz got very good, the skip distance shortened and the beacons around 2,400 kms were heard.
6) There is a fishing buoy on the WSPR frequency! It ID's itself as 'DJ' but seems a bit low in frequency so is not a issue.
7) Using WSPR to measure band conditions is somewhat limited by the number of people using it. For example, there is a lack of WSPR stations in the mid states of the USA. All you can use the WSPR map for is to gauge where the band is open to, not where it is not open to. The band can be wide open to southern Russia and there can be no WSPR spots.

Backscatter.........For anyone not familiar with the principles of back scatter, it works as follows....

A signal from a transmitter 'bounces' off the ionosphere and lands in a target area. A small percentage of that signal may be reflected back towards the TX due to mountains, waves on the oceans, etc. Received signals tend to be very weak.

Tuesday, October 2, 2012

Interesting conditions on the 10 metre band today. After starting off listing on WSPR for about two hours and then having a quick listen around the band, it was soon obvious that the conditions were better than the map on the WSPR website might suggest.

Came across P29FR in Papua New Guinea. He was weak but I could hear him giving 5/5 reports which was a sure sign he was working weak stations. So after a quick scramble in the drawer for the microphone.....one call....and P29FR was in the log! My first QSO since May 2011 ;o)

Conditions seemed to be pretty good around 11am with signals coming through from South-East Asia and Australia even though they were weak. I heard VK6APZ on the West Coast of Australia, HS0ZEX in Phuket Island in Thailand and later, I heard 9M2CQC in Malaysia on WSPR.

I also heard 5Z4/LA9PF in Kenya as well as the ZD9UW expedition on Tristan da Cunha in the South Atlantic....just about audible but way too weak to work. There were also plenty of signals from Eastern Europe...Ukraine and Russia as well as some strong signals from Cyprus and the Canary Islands.

I was kind of expecting it to open later to the US but it never happened. I heard some weak beacons from Argentina and Brazil but that was about all. I was hearing EA8FF on WSPR up until 18:48 UTC, some 40 minutes after local sunset here.

GW7PEO.......Of the European signals heard on WSPR on 28 MHz, one struck me as strange...GW7PEO in North Wales.

At 370 kms, it's an odd one. It's very close for Sporadic-E and I didn't seem to hear any of the other UK stations active at the time. It might have been via tropo?.......although I have my doubts. If he was on the west coast then I might think maybe but he is on the coast of North Wales with some high mountains to his south-west. Meteor scatter?.......although the requirement for a two minute burst and the lack of other UK stations tends to rule that one out. The only other possibility that I can think of was that it was via back scatter? F2 or Sp-E?

Looking at the WSPR spots above, GW7PEO at -23dB is buried deep in the noise. At roughly the same time, EA8FF is flying in with +8dB......obviously good F2 conditions to the south. My guess is backscatter via F2 but it's impossible to be sure.

Beacons heard on 28 MHz on Sunday, the 30th of Sept (Outside of Europe and N.America)

The distance to VK5WI/B is roughly 16,800 kms. Considering it was an hour or two after sunset in Australia, the signal may well have been enhanced by a tilting in the ionosphere and the signal arrived by chordal hop rather than the usual multi-hop reflections using the ground.Other non-European signals heard during the day were from South Africa, Argentina and Brazil....~9,400 to 10,800 kms. Nice distance but North-South propagation is nothing special on 10 metres.North-America......A large number of beacons were received again from N.America although the pattern was slightly different. On Sunday, there were fewer beacons from the arc from Florida to the Great Lakes but there were more from the north-east area of the US.

CW Beacons received from N.America on 28 MHz on Sunday, 30th Sept.

This was possibly because conditions were better than Saturday....i.e. MUF higher.....i.e. skip distance shorter. Again, there was an opening to the west coast as well with the beacon on Baffin Island making an appearance again.Later in the day, a station in Mexico City was heard as well as the person he was talking to in Newfoundland....single hop and double hop distances.Other observations over the weekend......1) Fishing Buoys........Those fishing buoys with the two letter cw id were heard again. Location? Could be anywhere.
2) OTHR..........On two occasions, I noticed a signal which I presume was OTHR....Over The Horizon Radar. It was 20 khz wide and was loud buzzing sound. It only seemed to last for a few minutes and it seemed to hop around as well. I heard it once on 28.290 MHz and also up around 28.320 MHz.3) Aurora.........There was an aurora on Sunday night and that really seemed to kill the band. On Monday, it was very poor with only some Sporadic-E signals from Spain making it through.4) GB3RAL.......I noticed the GB3RAL beacon is back working again. I heard several meteor bursts from it........'GB3R'......'AL IO'....and other fragments. All close to the early morning meteor scatter peak around 6am UTC. The signals are never very strong but considering the low power and the lack of gain on the transmit antenna there and the receive antenna here then it's not suprising.Overall........some nice conditions on the 10 metre band over the weekend. Not exactly wide open but still good solid F2 East-West signals which is a good sign. The signals I heard were nearly all beacons. I'm sure there might have been other DX signals on the band but beacons are a very good way to gauge conditions. If it's like this now, I wonder what will it be like in November and February???

After a long absence of over a year, I finally turned the radio back on again this weekend. My previous post is dated June 2011 so I guess I haven't listened in 15 months. It's hard to say exactly why I was off for so long? I guess it's perhaps that I lost the habit of turning on the radio and having a listen.

About a week ago, I started looking through some of the more recent issues of the IRTS Newsletter and some of the items there caught my interest. One in particular was the two part piece by EI5DD on WSPR and QRSS which was something I had spent a bit of time on in the past. This got me looking at some of the blogs that I 'follow'. One mentioned good conditions on 28 MHz and that was the trigger to turn on the rig last weekend.

Needless to say, some of the aerials are in a bad way after the year of neglect. I know I cut through some wire with the hedge clippers a few weeks back ;o) . Suprisingly enough, the 10m vertical still works fine! After all of the gales last Winter and Spring, it's still reasonably straight and the VSWR seems fine. There is perhaps a lot to be said for having a cheap half-wave CB antenna on a 4 metre pole as opposed to something better up at a greater height.

Solar Flux......The big difference in the last 15 months of course is the solar flux. In the Summer of 2011, the solar flux was down around the 100 mark whereas it is now up around 140. Looking at the graph for the current solar cycle, it is predicted to peak in mid 2013 so perhaps it's a good time to be back on the radio!

Conditions over the weekend......Sat 29th/Sun 30th Sept 2012.......I spent most of the time on the radio this weekend listening for the various beacons around 28.2 MHz. The best thing about the beacons is that they give a good snapshot of what conditions are like on the band which may not always be obvious when listening to SSB. I also have to admit that I have pretty much no interest in chasing DX or contests so I had no real interest in making loads of contacts.......a case of been there, done that.

The lists below are from the Saturday, the 29th of September. The items in bold are the ones of interest to me...

Sat 29th Sept......I switched on about 12 noon and the first beacons heard were from around Greece......around 3,000-3,500 kms which is one hop F2 signals so nothing special there. I was also hearing beacons in Brazil and Argentina which was obviously multi-hop but in general, North-South paths are nearly always the easiest on 28 MHz so still nothing special. Beacons around Florida were heard but again, that's the most southerly path to the USA and is nearly always the first part of the US to be heard. Even when the solar flux is much lower, it's not unusual to have openings to Florida.

What was interesting though were the beacons in the mid US. e.g. K0HTF/B in EN31 in Iowa (2.5w/GP) and W0ILO/B in EN16 in North Dakota. This is a more northerly path and means that conditions were good.

CW Beacons on 28 MHz heard from North America on Saturday, the 28th of September 2012

As you can see from the map above, most of the beacons heard were roughly in a broad arc going from Florida to the Great Lakes. This can be easily explained by the fact that it was most likely double hop F2 propagation.

For example, Florida is roughly 6,500 kms...too far for one F2 hop.....but perfect when you consider 2 x 3,250 km hops...a typical distance for signals on 28 MHz when the MUF is probably just up over 30 MHz. This also explains why nothing heard from the 1 or 2 call areas in the NE of the US....too far for one hop and too close for the second hop. In effect, the propagation footprint can be laid out like a series on concentric rings or doughnuts.

The only one hop signal heard to the west was VY0SNO/B in FR53rs in Baffin Island. This was also very close to half-way for double hop to the signals heard from California (2 x 4,000 kms = 8,000 kms). The fact that the 28 MHz signals went this far north is a sure sign of how good conditions were. There is something special about hearing the West coast of the US and Canada on 10 metres.

So was the band wide open on 28 MHz? Well....no. When it's wide open, you hear all the US call areas and then maybe Alaska and Hawaii. Conditions still have a way to go before they reach those reached during the last solar cycle.